Vessel dished end
As a curved base can be summarized the different soils, which are used as the final element of mostly cylindrical ( tubular ) pressure vessels and other process-related containers. Due to the flattened " hemispherical shape " they take up less space than the ideal for pressurizing hemispherical shape, with only slightly thicker wall thickness. A floor is made up of the average spherical cap (r1 ), the outer rims (r2 ) and the subsequent short cylindrical part which is called the board (h). Are standardized names dished bottom and basket-handle base with the associated radii ratios ( see below).
Basis for calculating the wall thickness calculation Dished for internal pressure resistance are present in Europe in the relevant regulations for the manufacture of pressure vessels according to the Pressure Equipment Directive 97/23/EC ( AD 2000 leaflet B3 as well as in the harmonized standard EN 13445-3 ). For other countries and regions other regulations such as ASME U ( in the U.S.) or the ML license ( in China) are valid. The greatest loads (stresses ) due to the internal pressure within the range of the brim. For this reason, notches and other deformations are to be avoided in this area.
The connection of the dished end of the cylindrical part of the container ( excess) is usually made by a continuous butt weld.
Dished bottom
When dished head according to DIN 28011 is r1 = Da and r2 = 0.1 * Da is the dished bottom ASME F & D r1 = Da and r2 = 0.06 * Since (R & D is an abbreviation for flanged and dished. In English, this form also referred to as like torispherical head)
The mold was by Georg Kloppsch (1874 - 1951) invented. Through this the egg modeled form, the container relative to the ideal shape of the hemisphere, relatively pressure-resistant.
The dished bottom is slightly flatter than the also common basket arch floor.
Dished bottom made of stainless steel: AD2000 - W2 HP7 / 3 8 / 1
Dished bottom made of carbon steel: AD2000 W1 HP7 / 2 8 / 1
Ellipsoidal soil
When ellipsoidal floor according to DIN 28013 r1 = 0.8 and r2 = 0.154 * Da * Da.
The basket- ground ( English (deep dished ) torispherical head, and in DIN 28013 ellipsoidal head or basket arch ) is slightly more curved than in the German area most commonly dished bottom. The ellipsoidal bottom comes the usual American -dimensional shape of the 2:1 elliptical dished very close.
Production
The production of such a floor is easier than that of a hemisphere. The preparation can be done in either a cold press method and in the hot pressing process; in general, however, by pressing the bottom of the first radius (R1), followed by crimping of the edge and hence of the second radius (r2). Dish bottoms are welded together also from individual segments.